| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3120587 | Archives of Oral Biology | 2016 | 8 Pages |
•A nine-species bacterial consortium resembling subgingival microflora was composed.•Proteolytic activity increased during the course of culture.•PAI-2 inhibited cell-associated and released bacterial proteolytic activity; in particular from P. gingivalis.
ObjectiveThe aim of this study was to investigate the ability of the serine protease inhibitor plasminogen activator inhibitor type 2 (PAI-2/Serpin B2) to inhibit proteases produced by a multispecies bacterial consortium in vitro.BackgroundGingival and periodontal inflammation is associated with an increased flow of protein-rich gingival fluid. This nutritional change in the microenvironment favors bacteria with a proteolytic phenotype, triggering inflammation and associated tissue breakdown. PAI-2 is produced by macrophages and keratinocytes and is present in very high concentrations in gingival crevicular fluid; the highest level in the body.DesignA multispecies bacterial consortium comprising nine bacterial strains, resembling the conditions in a periodontal pocket, was grown planktonically and as a biofilm. After seven days PAI-2 was added to the consortium and the proteolytic activity was assayed with fluorogenic protease substrates; FITC-labeled casein to detect global protease activity, fluorescent H-Gly-Pro-AMC for serine protease activity and fluorescent BIKKAM-10 for Porphyromonas gingivalis-associated protease activity. Protease activity associated with biofilm cells was examined by confocal scanning laser microscopy.ResultsPAI-2 inhibited proteolytic activity of the bacterial consortium, as seen by decreased fluorescence of all substrates. PAI-2 specifically inhibited P. gingivalis proteolytic activity.ConclusionTo our knowledge, this is the first time that PAI-2 has been shown to inhibit bacterial proteases. Given the high concentration of PAI-2 in the gingival region, our results indicate that PAI-2 might play a role for the integrity of the epithelial barrier.
